1. Field of the Invention
The present invention, in general, relates to milling machines and lathes and, more particularly, to a quick-release tool holder for rapidly changing tool bits and cutters.
Those skilled in the art of using milling machines and lathes know about changing tools. The terms “tool” or “tool bits” as used herein is intended to apply to any type of a rotary tool that actually contacts the work-piece and removes material from it. Drill, grinding, and cutting bits are included and are benefited by the instant invention.
The term, “rotary tools” is intended to include any tool that rotates the tool bit or work-piece and allows contact of the tool bit with the work-piece. Milling machines and lathes are examples of rotary tools.
It is often necessary to frequently change tool bits. This is time-consuming. It is also necessary for any device that expedites the process to securely hold the tool bit in a repeatable position; else inaccuracies and non-repeatability will occur. This is true for many numerically controlled (i.e., computer controlled) milling machines and other types of rotary machines (i.e., lathes, etc.) that are programmed to perform a repetitive operation on a plurality of work-pieces.
The tool bit must be centered by any tool holder. The tool holder must also be able to transmit a great deal of torque to the actual tool bit, as the tool bit contacts the work-piece.
These needs are true for a variety of rotary tools, including lathes and milling machines. A smaller class of milling machines experiences frequent tool bit changes and would especially benefit from such a device.
Accordingly, there exists today a need for a quick-release tool holder for rotary tools that helps ameliorate the afore-mentioned difficulties.
Clearly, such an apparatus would be a useful and desirable device.
2. Description of Prior Art
Tool holders are, in general, known. Prior art tool holders do not adequately center each successive tool bit. Some devices introduce an offset mass in the tool holder that causes vibration during rotation of the tool bit, or which may snag on an operator's clothing. Also, prior devices do not adequately remove slack and so the actual tool bit is not held with sufficient rigidity.
While the structural arrangements of the above described devices may, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.